Chromotropic acid,monosodium salt, 2,7-Naphthalenedisulfonic acid,4,5-dihydroxy-,monosodium salt, sodium 4,5-dihydroxy-7-sulfonaphthalene-2-sulfonate, CHROMOTROPIC ACID SODIUM SALT, Sodium hydrogen 4,5-dihydroxynaphthalene-2,7-disulphonate, EINECS 223-430-2